Brakes

Gene Heagney · Posted: Sun Oct 11, 2009 8:55 am Post subject: Brakes

Just wondering how hard the brakes are supposed to grab. With the kart on the stand, should I be able to turn the tire with the brakes applied? Or do they brakes need to lock down harder than that?

As of now, I can get a good grip on the tire and turn it. It's not really easy... but I can turn it. And I'm not a bodybuilder by any means haha.

Larry Andrews · Posted: Sun Oct 11, 2009 10:04 am Post subject: Re: Brakes

Gene Heagney · Posted: Sun Oct 11, 2009 11:08 am Post subject:

Its ok.. thanks for responding.

I've re-built all the capilers and both master cylinders. It's a good possibility that I didn't bleed them good enough. But its also a good possibility that the master cylinders are done. They had some pretty nasty grooves. I tried to clean them up... but they might be junk.
But I'll try bleeding the brakes good again. Maybe I'll get lucky and that will help..

I just don't know what normal is for a shifter kart, so I figured I'd try and find out before I assumed wheter they are good or not. Thanks again.

Larry Andrews · Posted: Sun Oct 11, 2009 4:09 pm Post subject:

If there's grooves in the master cylinder, pressurised fluid could be getting back past the seals. If it is, the piston will pull air back past the seals every trip back and forth. Once air's in there, brakes go away.

I tried sanding out the grooves, but found the bores were so wobbly (?) that it was pointless. Once I got through the anodizing, the aluminum just melted away. Not sure what brakes you've got, but the wildkart masters were only $70 each (a few years back) and made a huge improvement. It looks like they now sell a self-adjusting m/c but I bet they're about $200 each.

Of course, the wheel cylinders were nearly as bad and replacement parts or sleeving was going to be nearly $500.

Gene Heagney · Posted: Sun Oct 11, 2009 4:34 pm Post subject:

Yeah I think the master cylinders are shot. I put fluid in yesterday and bled them. Went back today and the kart still felt like it had about as much pedal as it did yesterday (hard to tell because I was by myself today so I didn't have someone to either hold the pedal or try and turn the wheels). But I noticed fluid finding its way out of the bore on the master cylinder.
I have an older Birel with the older style Freeline brakes. I'm not sure that the calipers are all that bad. When I had them apart they didn't look terrible. And I honed them very lightly. So I guess I'm gonna try new master cylinders and see if that solves the problem.
What do you think about using MCP master cylinders with the freeline's? I'm guessing I'll have to go with the billet (if at all), or can I go with the standard?

Larry Andrews · Posted: Sun Oct 11, 2009 11:20 pm Post subject:

Gene - dono about the Birel brakes, never had or worked on one and their hardware seems first-rate. Am pretty sure that you'll be able to get a lot of choices when all is said and done - it's sort of a matter of how much work and cash do you want to put into the kart?

Does sound like new m/c's will help a lot.

I can give you some tips on getting the bores sleeved if you need...

Benn Herr · Joined: 18 Jul 2001 Posts: 1580

Bill Martin · Posted: Mon Oct 12, 2009 12:12 pm Post subject:

Benn Herr · Joined: 18 Jul 2001 Posts: 1580

Bill,

It's adjustable, just not quickly! Once you find the balance you need you hardly ever change it. The bosses are just welded onto a standard arm that has been cut down. Make sure the bosses are think enough to withstand the heat without distorting, Trim the arms to fit, clean all the cad plating off and have a good welder do his stuff. Oh, and don't try welding on the arms with out taking them off the masters! I don't have any real good pictures but these should help.

I made our bosses out of 5/8" solid steel and drilled and tapped them. The rod ends are 5/16". Use good quality ends - it's important! 5/16" is also about the minimum diameter you can use for the balance bar. Any smaller and it will bend when you use it.
_________________
Benn Herr
Come see our Superkart Build Off @
http://www.lostenduros.com/?page_id=1534
beherr3@cox.net
http://www.southwestkarters.com/
http://www.lostenduros.com/
Kart Design
Chandler, Az.

Bill Martin · Posted: Tue Oct 13, 2009 1:16 pm Post subject: extra pictures

Mike Goebel · Posted: Tue Oct 13, 2009 3:37 pm Post subject:

The thing that always scares me on those masters is those tiny pivot pins.

Mike G.

Benn Herr · Joined: 18 Jul 2001 Posts: 1580

Robbie Nelson · Joined: 26 May 2008 Posts: 132

Benn,

Is that a Birel chassis? If so, is that the stock master cylinder bracket or is has it been extended?

Let me get to my root question... Will the MCP master cylinders bolt right on to my CR32X chassis or will I need to modify the bracket?

Benn Herr · Joined: 18 Jul 2001 Posts: 1580

Robbie,

The MCP will not bolt straight on to your Birel, you'll have to rat-tail out one of the holes a little bit. The extended tab on our Birel kart is because the rear brake line I had was too short! I have a welder and a drill and the steel - but I couldn't wait for the right line to get here.

The things you do on a Friday night. Smile

_________________
Benn Herr
Come see our Superkart Build Off @
http://www.lostenduros.com/?page_id=1534
beherr3@cox.net
http://www.southwestkarters.com/
http://www.lostenduros.com/
Kart Design
Chandler, Az.

Brian Wilhelm · Posted: Fri Nov 30, 2012 12:01 pm Post subject: ?

Check out the adjustable bias bar Russell Karing sells.
_________________
Brian